Installing a performance camshaft from Comp Cams is the quickest way to completely transform the attitude and output of a classic Chevy small-block or big-block. Unlike bolting on an intake or headers, a cam swap rewrites the engine's power delivery, shifting the torque curve and creating that distinctive, aggressive exhaust note. This guide provides a professional-level roadmap for installing a high-end Comp Cam kit, typically costing around $1,200, covering everything from selecting the correct grind to the critical process of degreeing the cam and setting up the valvetrain for reliability.

Understanding Camshaft Specs and Choosing the Right Comp Cam

Before you buy, you need to match the cam to the vehicle's weight, rear gear ratio, torque converter stall speed, and engine displacement. A $1,200 kit usually represents a complete retro-fit hydraulic roller assembly. This is the gold standard for modernizing vintage Chevy blocks that originally came with flat tappets. The kit typically includes the camshaft, hydraulic roller lifters, valve springs, retainers, locks, and a timing set.

Comp Cams offers several families of grinds. The Thumpr series is designed for a radical idle and strong mid-range, perfect for a street cruiser that sees mostly weekend action. The Xtreme Energy family is a more performance-oriented choice, prioritizing broad torque and horsepower across the curve. For a dedicated strip car, a Solid Roller grind unlocks the highest RPM potential. You can browse the full Comp Cams catalog to see their specific recommendations based on your exact engine code and vehicle application.

Selection Tip: A common mistake is choosing a cam that is too aggressive for the rest of the combo. A cam with too much duration will kill low-end torque and require a high-stall converter and steep gears. A well-matched cam makes the entire system feel stronger.

Required Tools and Workspace

You will need a standard mechanics tool set, but a cam swap also requires specialty tools. Having these on hand before you start prevents frustration.

  • Comp Cam Kit (Cam, lifters, springs, retainers, locks, timing set)
  • Complete socket set, ratchets, and extensions (SAE and Metric)
  • Torque wrench (ft-lb and in-lb)
  • Cam Degree Kit (Degree wheel, dial indicator, magnetic base, piston stop)
  • Harmonic balancer puller and installer
  • Camshaft installation handle (or long bolt)
  • Assembly lube (Comp Cams recommended break-in lube)
  • New gasket set (timing cover, intake manifold, valve covers)
  • Engine oil primer tool (for the oil pump)
  • Thread chasers and tap set (for cleaning bolt holes)
  • Shop towels, safety glasses, and nitrile gloves

Step 1: Engine Preparation and Disassembly

While it is possible to swap a cam with the engine in the car, it requires some contortion. Pulling the engine makes the job cleaner and allows for closer inspection of the cam bearings.

Start by disconnecting the battery to prevent any accidental cranking. Drain the cooling system and remove the radiator. The intake manifold, carburetor, and distributor must come off. This gives you access to the valley pan and the lifter bores. Remove the valve covers, rocker arms, and pushrods. Pull the spark plugs to make rotating the engine by hand easier.

Removing the Lifters: This is a critical detail. The lifters must come out before the cam can slide forward. If you are reusing the lifters (not recommended with a new cam), store them in a labeled tray to ensure they return to the same bore. For a performance cam swap, always install new lifters. The wear pattern on old lifters is specific to the old cam lobes.

Step 2: Exposing and Removing the Factory Camshaft

With the front of the engine exposed, remove the fan belt, water pump, and harmonic balancer using a puller. Unbolt the timing cover. You will now see the timing chain and gears.

Rotate the engine to Top Dead Center (TDC) on the compression stroke for cylinder #1. Align the timing marks on the cam gear and crank gear. Remove the timing chain and gears. Unbolt the camshaft thrust plate or retainer plate. The camshaft can now slide out the front of the engine block. Be extremely careful not to gouge the cam bearings. Slowly rotate the cam as you pull it out, lifting it slightly to clear the block.

Inspect the Bearings: Look at the cam bearings in the block. If they show scoring or excessive wear, the engine should go to a machine shop. A new cam in worn bearings will fail quickly. If they look clean and tight, and the old cam spun freely, proceed with confidence.

Step 3: Installing the New Comp Cam and Timing Set

Preparation is everything at this stage. Take the new Comp Cam out of the box and liberally apply Comp Cams break-in lube to every single cam lobe and distributor gear. Coat the lifter bottoms and sides with the same lube. This is not optional; the initial startup sees the most metal-to-metal contact before the oil pressure builds.

Slide the new cam into the block slowly, rotating it to engage the cam bearings. Install the thrust plate and torque to spec. Now install the new timing set. Use a high-quality double-roller chain set. Align the timing marks as per the instructions. Important: Do not just trust the dots without verifying. Install the cam gear and crank gear with the chain. Torque the bolts in stages.

Step 4: Degreeing the Camshaft (The Most Critical Step)

Degreening the cam ensures the camshaft's lobes are phased correctly to the crankshaft. Manufacturing tolerances in the crank keyway and timing gear sets can shift the cam timing by several degrees. A cam installed "dot to dot" can be 4-6 degrees off. This kills performance.

Here is the process at a high level:

  1. Find True TDC: Install a piston stop in cylinder #1. Rotate the crank until the piston hits the stop. Mark the degree wheel. Rotate the crank the other way until it hits the stop. Mark the wheel. True TDC is exactly halfway between those two marks. Rotate the crank to that point.
  2. Install the Dial Indicator: Mount the dial indicator on a rocker stud or intake bolt. Position it on the #1 intake valve retainer or the lifter pushrod seat.
  3. Find Intake Centerline: Rotate the crank forward until the dial indicator shows maximum lobe lift. Zero the dial. Rotate the crank backwards (to take up slack) then forward to .050" lift before max. Record the degree wheel number. Rotate through max, then forward again to .050" on the closing side. Record that degree wheel number.
  4. Calculate the Centerline: Add the two numbers together and divide by two. This is the intake centerline. Comp Cams provides a specification card with the cam. If it says 108 degrees, and you find 106 or 110, you need to adjust the cam timing using offset bushings or keys.
Pro Note: Taking the time to degree the cam guarantees you are getting the exact power band you paid for. A retarded cam shifts power high, an advanced cam shifts power low. Straight up is where the cam maker designed it. Summit Racing has detailed degree wheel kits if you need one.

Step 5: Valvetrain Assembly and Geometry Check

With the cam timed correctly, you must ensure the valvetrain geometry is correct. Install the new lifters into their bores. Install the new pushrods. A cam with different lift may require different length pushrods. Use an adjustable pushrod checker to find the correct length for proper rocker arm geometry. The goal is for the rocker tip to sweep the center of the valve stem at mid-lift.

Install the new valve springs provided in the $1,200 kit. Check the installed height using a spring height micrometer. If the springs are too tall, you lose seat pressure. If too short, you risk coil bind. Use shims to achieve the correct installed height. Install the retainers and keepers. Check for valve train clearance by slowly rotating the engine by hand twice. Ensure nothing binds.

Step 6: Reassembly and Pre-Oiling

This is the reverse of teardown. Clean the block surface thoroughly. Install the timing cover with a new seal and gasket. Install the harmonic balancer using the correct installer tool. Do not hammer it on. Install the intake manifold with high-quality gaskets and thread sealant on the bolts that go into the water jacket.

Before reinstalling the distributor, you must prime the oil system. Use a primer tool in an electric drill. Spin the oil pump until you see oil coming out of every rocker arm. This verifies the oil passages are clear and the lifters are pumped up. If the rockers don't oil immediately, stop and investigate. Install the distributor, set initial timing to 10-15 degrees BTDC.

Step 7: First Fire and Break-In Procedure

Fill the engine with break-in oil (non-synthetic, high zinc) and coolant. Connect the fuel and power. Start the engine. For a hydraulic roller cam, you do not have the aggressive flat tappet break-in, but you must still follow a strict procedure.

  • Immediately raise the idle to 2000-2500 RPM. Do not let it idle below 2000 RPM for the first 20 minutes. This stabilizes oil pressure and ensures the lifters are rotating and oiling properly.
  • Check for leaks (water, oil, vacuum).
  • Listen for valvetrain noise. A slight noise is normal as lifters pump up. A loud clicking means a geometry issue or a lifter failure.
  • After 20 minutes, shut it down. Let it cool completely. Re-torque the intake manifold bolts.

Step 8: Post-Break-In Tuning and Street Driving

Now you need to tune the engine for the new cam. A performance cam creates less vacuum at idle. You must adjust the carburetor idle mixture and idle speed screws to compensate. You may need to open the secondary throttle blades slightly to expose the transition slots.

Timing Curve: The new cam will want more total timing. Check your total mechanical advance. Most performance small blocks like 34-38 degrees total timing all in by 2500-3000 RPM. Adjust your distributor (or purchase an adjustable vacuum advance) to match.

Test Drive: Take the car for a short drive. Accelerate gently at first. Listen for detonation (spark knock). If you hear pinging, back off the timing or add higher octane fuel. Install a vacuum gauge; tune the idle mixture screws for the highest steady vacuum reading.

Common Overlooked Details

  • Distributor Gear: A billet steel camshaft requires a melonized or bronze distributor gear. A standard cast iron gear will wear out the billet cam gear quickly.
  • Valve Spring Height: Do not skip checking installed height. Incorrect height leads to premature spring failure or valve float.
  • Pushrod Clearance: Check that the new pushrods do not hit the cylinder head pushrod slots at full valve lift.

Conclusion

Installing a $1,200 Comp Cam kit is a serious investment of time and money. By following this guide and focusing on the details that matter most—lubrication, degreeing, valvetrain geometry, and proper break-in—you are setting yourself up for success. The result is a classic Chevy that runs stronger, sounds meaner, and delivers a driving experience that makes all the hard work worthwhile. Hit the key, listen to that cam lope, and enjoy the muscle gains.